This invention relates, in general, to semiconductor products, and more particularly, to making semiconductor devices.
Generally, most very large scaled integrated (VLSI) semiconductor circuits are manufactured by depositing and patterning conductive and nonconductive materials or layers and by stacking the layers on top of each other. As devices become more sophisticated and more complex, the number of layers stacked on each other tends to increase, and as the number of layers increase, planarity problems generally occur. Much attention has been given to solving these planarity problems or issues concerning interior portions of the semiconductor circuit; however, little attention has been given to solving periphery planarity issues and more particularly to solving planarity problems of bonding pads or probe pads of the semiconductor circuit.
At present, most VLSI semiconductor circuits use one or two levels of metal to interconnect the semiconductor devices on a VLSI semiconductor circuit. However, as semiconductor VLSI devices have become more complex, the number of metal layers required to interconnect the semiconductor devices increases. Generally, by increasing the number of metal layers to more than two, several problems occur while fabricating bonding pads and probe pads, such as control of critical dimensions and metal thinning at peripheral edges of the bonding pads or probe pads.
These problems generally are caused by a lack of planarity of the bonding pads or probe pads in relation to the interior of the semiconductor VLSI devices. As the complexity of VLSI semiconductor circuits increase and the number of metal layers increase, severity of the nonplanarity of bonding pads and probe pads will also increase.
Therefore, a method for planarizing bonding pads and probe pads would be highly desirable. Also, by achieving more planar bonding pads and probe pads, an increased control of critical dimensions would result, and metal thinning at the edges of the bonding pads or probe pads would be greatly reduced or eliminated.